1. Y2O3-Al2O3 microsphere crystallization analyzed by electron backscatter diffraction (EBSD)Wolfgang Wisniewski, Anna Prnová, Peter Švančárek, Milan Parchovianský, Dušan Galusek, 2020, original scientific article Abstract: The crystallization of glass microspheres in the Y2O3–Al2O3-system produced from precursor powders of four different nominal compositions via flame synthesis is analyzed in detail by electron microscopy with a focus on electron backscatter diffraction (EBSD). Growth models are formulated for individual microspheres crystallized during flame synthesis as well as after an additional heat treatment step. 16 different types of crystallized bodies are cataloged for future reference. They are presented without regard for their relative occurrence; some are extremely rare but illustrate the possibilities of flame synthesis in the analyzed system. All three phases in the binary Y2O3–Al2O3-phase diagram (Y3Al5O12, YAlO3 and Y4Al2O9) and α-alumina are located by EBSD. Energy dispersive X-ray spectrometry results obtained from these microspheres show that their chemical composition can deviate from the nominal composition of the precursor powder. The multitude of differing microsphere types showing polygon and dendritic crystal growth as well as phase separation indicate that flame synthesis can lead to a wide variety of parameters during microsphere production, e.g. via irregular flight paths through the flame, contaminants or irregular cooling rates. Keywords: Y2O3-Al2O3, microsphere crystallization, flame synthesis, EBSD Published in DiRROS: 23.07.2024; Views: 206; Downloads: 160 Full text (6,57 MB) This document has many files! More... |
2. Relevance of cold-rolling technology for the texture and anisotropy of EN AW-8011A aluminum alloysJakob Kraner, Kyung Il Kim, Bonghwan Kim, Shae K. Kim, Irena Paulin, 2023, original scientific article Keywords: aluminium alloys, cold rolling, SEM-EBSD, textures, anisotropy Published in DiRROS: 08.03.2024; Views: 410; Downloads: 224 Full text (2,04 MB) This document has many files! More... |
3. High-temperature oxidation of boiler steels at 650 °CJaka Burja, Barbara Šetina, Borut Žužek, Tilen Balaško, 2023, original scientific article Abstract: This study presents a comprehensive investigation of the formation, composition and
behaviour of oxide layers during the high-temperature oxidation of four different steel alloys (16Mo3,
13Cr, T24 and P91) at a uniform temperature of 650 °C. The study is aimed at assessing the oxidation
damage due to short-term overheating. The research combines CALPHAD (CALculation of PHAse
Diagrams) calculations, thermogravimetric analysis (TGA) and advanced microscopy techniques, in-
cluding scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD), to elucidate
the complex mechanisms controlling oxidation kinetics and oxide layer development. CALPHAD
calculations were used to determine the thermodynamically stable phases for each steel type at 650
◦C and different oxygen activities. The results showed different phase compositions, highlighting
the importance of the chromium content in steel for the formation of oxide layers. The different
oxidation kinetics and oxide layer compositions are presented and associated with the increased risk
of material degradation due to overheating. These results have significant implications for industrial
applications, mainly the susceptibility to oxidation of low-alloyed steels like 16Mo3 and 13 Cr and
contribute to a deeper understanding of oxidation processes in steels. Keywords: high-temperature oxidation, thermogravimetric analysis, kinetics, CALPHAD, boiler steels, SEM, EBSD Published in DiRROS: 26.01.2024; Views: 524; Downloads: 263 Full text (12,99 MB) This document has many files! More... |
4. The influence of the hot-rolling technique for EN AW-8021B aluminium alloy on the microstructural properties of a cold-rolled foilJakob Kraner, Tomaž Smolar, Darja Volšak, Marjana Lažeta, Robert Skrbinek, Damijan Fridrih, Peter Cvahte, Matjaž Godec, Irena Paulin, 2021, original scientific article Keywords: aluminium alloys, hot rolling, microstructure, EBSD, burst test Published in DiRROS: 06.05.2022; Views: 866; Downloads: 245 Link to file |